With progress of the two-dimensional imaging devices (two-dimensional imaging elements) such as CCD cameras, a method for direct and high speed digitization with a two-dimensional imaging device is expected to be dominant in digitizing technology of two-dimensional image over the conventional digitizing method by moving a one-dimensional imaging device such as a scanner.
As a prior art using an integrating sphere, a method and a system to convert an object image to a digital image signal is disclosed in the patent document 1 described below.
In addition, standard optical source devices are disclosed in the patent documents 2, 3, and 6 described below.
Furthermore, as a conventional technology by the inventor of the present invention, a high speed, high precision digitizing system by combining a CCD camera with high speed imaging capability and an integrating sphere is disclosed in the patent document 4 below, and a technology of disposing a planar optical diffusive device at the opening of an integrating sphere as a light source in order to take an image of a light source only is disclosed in the patent document 5 below
[Patent Document 1]
Japanese Patent Application Laid-Open 7-15658
[Patent Document 2]
Japanese Utility Patent Application Laid-Open 50-21586
[Patent Document 3]
Japanese Patent Application Laid-Open 11-173913
[Patent Document 4]
Japanese Patent Application Laid-Open 2003-110813
[Patent Document 5]
Japanese Patent Application Laid-Open 2003-177061
[Patent Document 5]
US Patent Application 2003-0185004A1